Vibration-isolating apparatus and metal stopper therefor

ABSTRACT

A vibration-isolating apparatus and a metal stopper having an excellent and lasting reliability comprises an outwardly projecting stopper rubber, and a metal stopper fixed to a first fixture so as to surround the stopper rubber. The metal stopper has a first contact surface in parallel with a compression-direction-facing surface of the stopper rubber, a second contact surface in parallel with a radial-direction-facing surface of the stopper rubber and a third contact surface in parallel with a drawing-direction-facing surface of the stopper rubber, and a fourth contact surface in parallel with a circumferential-direction-facing surface of the stopper rubber. The third contact surface inclines at an angle range of 10°-50° with respect to a plane perpendicular to the compression and drawing directions, while an inner edge of the third contact surface projects radially inward from the second contact surface by not less than 10 mm so as not to contact with the vibration-isolating base body.

RELATED APPLICATION DATA

The present application is a continuation of application Ser. No.09/548,422, filed Apr. 13, 2000.

BACKGROUND OF THE INVENTION

This invention relates to a vibration-isolating apparatus adapted tosupport a vibration generating member, such as an engine of anautomobile in a vibration isolating manner with respect to a body.

As the space saving techniques for the interior of an engine room of anautomobile produced in recent years have been developed, functionalparts have been miniaturized and arranged in a very narrowly spacedcondition. Therefore, the conditions for repairing the functional partshave become increasingly severe, and the creation of functional parts ofhigh durability and reliability has been demanded.

JP-Y1-1993-003789 (JP-Y1-05003789 or Japanese Utility Model PublicationExamined No. 3789/1993) discloses a vibration-isolating apparatus(hereinafter referred as Prior Art 1) of the following structure, forsupporting an engine in a vibration-isolating manner in such an engineroom with respect to a vehicle body. This vibration-isolating apparatuscomprises a first fixture secured to a bracket of an engine; a secondfixture secured to a body; a vibration-isolating base body formed of anelastic material such as rubber interposed between and connectingtogether these two fixtures; a stopper rubber projecting outward fromthe portion of the vibration-isolating base body which is on the side ofthe second fixture; and a metal stopper fixed to the first fixture so asto surround the stopper rubber. The metal stopper and stopper rubberprevent an excess deformation of the vibration-isolating basebody. Themetal stopper is formed of a metal plate by bending the same so as tohave a substantially sideway-fallen J-shaped cross section so that themetal stopper has contact surfaces respectively parallel to stoppersurfaces of the stopper rubber, stoppering action is achieved in all ofthe following three directions—compression and drawing directions inwhich the first and second fixtures are moved relatively toward and awayfrom each other; a radial direction perpendicular to these directions,for example, forward or backward direction of the vehicle; and acircumferential direction, for example, rightward or leftward directionof the vehicle. This metal stopper prevents damage on the elasticmaterial constituting the vibration-isolating base body and stopperrubber.

On the other hand, JP-A-1997-079310 (JP-A-09079310, or Japanese PatentPublication Unexamined No. 79310/1997) discloses anothervibration-isolating apparatus (hereinafter, referred as Prior Art 2) ofthe following structure. This apparatus includes a metal stopper whichhas the same shape as mentioned above and serves for restringdisplacements between upper and lower fixtures in all of followingdirection—compression and drawing directions in which the first andsecond fixtures are moved relatively toward and away from each other; aradial direction perpendicular to these directions, for example, forwardor backward direction of the vehicle; and a circumferential direction,for example, rightward or leftward direction of the vehicle. The metalstopper is formed by bending a plate or sheet so as to have asubstantially sideway-fallen J-shaped cross section and so as to becombined firmly with the first fixture. The metal stopper is bondedfirmly to an upper part of a vibration-isolating base body formed of anelastic member such as rubber, in such a manner that the metal stopperis opposed to a stopper rubber.

In such vibration-isolating apparatuses, the durability and reliabilitythereof have increasingly been demanded. Especially, because anupward-facing contact surface of the metal stopper, which surface abutson the stopper rubber when the metal stopper is displaced greatly in thedrawing direction, has to come to the lower side of the stopper rubberby moving around the stopper rubber, it is desired that a slip-off ofthe metal stopper can be prevented even when a momentary large stress indrawing direction is applied.

However, the above-described vibration-isolating apparatus of Prior Art2 is not satisfactory concerning its ability to prevent a slip-off ofthe metal stopper.

In view of the above, the present invention is aimed to provide avibration-isolating apparatus and a metal stopper therefor which have along-lasting durability and reliability.

As for Prior Art 1, in which a metal stopper is formed so as to surrounda stopper rubber in three directions, the spatial dimensions for astopper mechanism increases to cause a problem to occur in themountability thereof.

The vibration-isolating apparatus supporting the engine is fixed in arightwardly or leftwardly inclined state to a bracket in a vehicle.Therefore, whereas a large stress in rightward or leftward directionrarely cause an excessive stress to be exerted on other parts on thevehicle, a large stress in forward or backward direction causes thestopper rubber to collide with the metal stopper. By the collision,bending stress is exerted on fixing bolts for the second fixture on thelower side due to the reaction ascribed to the impact of the collision.This exerts an ill influence upon the sealability and fastening forcebetween the lower side fixture and fixing bolts, and causes problems tooccur in the reliability of the apparatus.

In the Prior Art 2, the metal stopper is merely formed by bending aplate or sheet so as to have a substantially sideway-fallen J-shapedcross section. Since this metal stopper has a structure not interferingwith the stopper rubber at displacements in the circumferentialdirection or the forward or backward direction, the mountability of theapparatus is high as compared with that of the Prior Art 1, while thefixture does not have an ill influence upon the fixing bolts. However,since the metal stopper is bonded firmly with the elastic body atvulcanization of the elastic body, rubber burr is left on the metalstopper, so that the controlling of a stopper clearance, or distancebetween abutting surfaces, is difficult.

The metal stopper maybe formed separately from the elastic body andassembled thereto later so as to eliminate the problems due to therubber burr. However, because the metal stopper is formed by merelybending a plate material so as to have a substantially sideway-fallenJ-shaped cross section, a required rigidity of the metal stopper cannotbe maintained against a large stress in the compression and drawingdirections or in the lateral direction. When a flange is formed bybending the edges on circumferential-direction-wise end of the metalstopper in order to maintain the rigidity of the metal stopper, theflange necessarily hits the stopper rubber. Consequently, the Prior Art2 has problems similar to those of the Prior Art 1.

In view of the above, second object of the present invention is solvingat once the above-mentioned problems of the prior art, and for achievingaltogether following—the improvement of the mountability of theapparatus; the prevention of circumferential-direction-wise interferenceof the metal stopper with the stopper rubber; and an increase in therigidity of the metal stopper.

BRIEF SUMMARY OF THE INVENTION

First aspect of the present invention provides a vibration-isolatingapparatus, having a structure basically identical with Prior Arts 1 and2, capable to prevent a slip-off of the metal stopper in the drawingdirection by improving the metal stopper, and thereby improve thedurability and reliability of the apparatus.

According to the first aspect, the vibration-isolating apparatusincludes a first fixture; a second fixture; a vibration-isolating basebody interposed between these two fixtures and formed of an elasticmaterial having rubber-like elasticity; a stopper rubber projectingoutward so as to restrict a large displacement of thevibration-isolating base body; and a metal stopper surrounding thisstopper rubber; and the metal stopper being formed by bending a metalplate or sheet. The metal stopper has contact surfaces respectivelyparallel to stopper surfaces of the stopper rubber, for restrictingdisplacements in following direction—a compression direction in whichthe first and second fixtures are moved relatively toward each other; adrawing direction in which the first and second fixtures are moved awayfrom each other; a radial direction perpendicular to the compression anddrawing directions; and a circumferential direction. A drawing-sidecontact surface of the metal stopper, which is for restricting adisplacement in the drawing direction, inclines in an angle range of10°-50° with respect to a plane perpendicular to the compression anddrawing directions. An inner edge of the drawing-side contact surfaceprojects inward from the radial-direction-wise contact surface by adistance which is not smaller than 10 mm, and which permits the inneredge not to contact the vibration-isolating basebody. Thus, a slip-offof the metal stopper can be prevented even when a large deformationoccurs momentarily in the vibration-isolating base body.

The reason why the angle of inclination of the drawing-side contactsurface and the distance by which the inner edges of the drawing-sidecontact surface projects are set in the mentioned ranges in thisvibration apparatus is following—these ranges constitute the necessaryand satisfactory conditions for meeting requirements of manufacturingand designing the metal stopper with respect to strength and rigidity.For example, when the angle of inclination is smaller than 10°,difficulties occur in the manufacturing of the metal stopper, and, whenthe angle of inclination exceeds 50°, there is a fear that the metalstopper slips off when a momentary large displacement of thevibration-isolating base body occurs. When the distance by which theinner edge of the drawing-side contact surface is smaller than 10 mm,there is a fear that the metal stopper slips off when a momentary largedisplacement of the vibration-isolating base body occurs.

In order to prevent the metal stopper from being slipped off, it isdemanded that the metal stopper has such rigidity and strength that doesnot cause the metal stopper to be elastically deformed even with respectto a momentary large deformation of the vibration-isolating base body.To meet this requirement, it is preferable to set the thickness of themetal stopper large, and secure the rigidity and strength thereof.Generally, the stopper rubber has following structure—a part of an outercircumferential edge of the second fixture is extended radially; anenclosing rubber portion encloses this extended portion; the stopperrubber comes into contact with the metal stopper when thevibration-isolating base body is greatly deformed. Accordingly, it isdesirable to set the thickness of the metal stopper larger than that ofthe extended portion extended from the second fixture, which portion isenclosed in the stopper rubber.

In order to increase the rigidity and strength of the metal stopper, itis preferable that outwardly extending flanges are formed on edgeportions of circumferential-direction-wise contact surfaces while anangle at which the flanges are bent set in the range of 45°-90° so as towithstand a large stress.

This vibration-isolating apparatus maybe of various kinds as long as ithas a stopper mechanism and preferably have high vibration isolating anddamping performance.

Second aspect of the present invention is to achieve the second objectof the invention mentioned earlier, by adopting the following structurefor the metal stopper.

A vibration-isolating apparatus of this aspect of the invention, whichhas same basic construction as in the first aspect of the invention,comprises a first fixture on the upper side; a second fixture on thelower side; a vibration-isolating base body formed of an elastic memberhaving rubber-like elasticity; a stopper rubber projecting outward fromthe portion of the vibration-isolating base body which portion is on theside of the lower side fixture; and a metal stopper opposed to thestopper rubber. The stopper rubber and the metal stopper serves forrestricting displacements in-an axial direction in which the first andsecond fixtures are moved relatively toward and away from each other,and in a radial direction. The metal stopper further comprising areinforcing flange for enhancing. rigidity of the metal stopper, beingformed to be continuous radially by downwardly bending an edge of themetal stopper except for a region that is subject to interference of thestopper rubber at a time of large displacement of the metal stopper in acircumferential direction relative to the stopper rubber; and a rigidreinforcing rib projecting outward from a circumferential-direction-wisecenter portion of the metal stopper except for a region having thereinforcing flange, so that the rigid reinforcing rib and thereinforcing flange are formed to be continuous in the radial directionover whole radial dimension of the metal stopper in view from thecircumferential direction.

Owing to such a structure, the metal stopper does not interfere with thestopper rubber when the vibration-isolating base body is displacedgreatly in the circumferential direction, while the bending rigidity ofthe metal stopper is improved. Furthermore, since the reinforcingflanges extend downward, the circumferential dimension thereof does notincrease, while the efficiencies or easiness for fixing and mounting themetal stopper is improved. Since the metal stopper is formed separatelyfrom the elastic body, the controlling of a distance between the metalstopper and the stopper rubber can be done easily, unlike a similarcontrol operation in the prior art.

The reasons for providing the rigid reinforcing rib so as to projectoutward from a circumferential-direction-wise center portion of themetal stopper reside in that, when the. reinforcing rib is formed on acircumferential-direction-wise end portion, it substantially becomes anextension of the reinforcing flanges and interferes with the stopperrubber at a large displacement in the circumferential direction. Whenthe reinforcing rib is projected inward, it also interferes with thestopper rubber.

Forming the reinforcing flanges and reinforcing rib continuously in thelateral direction mentioned above does not mean that both of these partsare in a physically continuous state but it means that the reinforcingflanges and reinforcing rib are joined together in the radial directionwhen the metal stopper is viewed in the circumferential direction. Thereinforcing flanges may not be formed over the whole radial dimension ofthe metal stopper as long as the metal stopper can secure apredetermined level of bending rigidity. The reinforcing flanges may beformed to be starting from a radially outside intermediate portionthereof. Concretely speaking, the reinforcing flanges may be formed tobe starting from a radial-direction-wise intermediate part of a flatportion that will be described later.

The metal stopper is opposed to the stopper rubber provided on theradially outer side of the elastic body that is bonded to upper andlower fixtures at a vulcanization process. The metal stopper is formedby press-working one single piece of pressed steel plate. The metalstopper has a flat plate portion contacting the upper fixture; an upperstopper portion extending from one radial-direction-facing edge of theflat plate portion; a radially-inward-facing stopper portion continuingfrom the upper stopper portion; and a lower stopper portion continuingfrom the radially-inward-facing stopper portion. Thus, stopper functionsare displayed against displacements in axial and radial directions.

It is especially desirable for combining a construction of the lowerstopper portion in the first aspect of the invention to this secondaspect of the invention, in order for preventing a slip-off of the metalstopper when a large deformation of the vibration-isolating base bodyoccurs in the drawing direction. Namely, the angle of inclination of.the lower stopper portion is set in the range of 10°-50° with respect toa plane perpendicular to a vertical direction in which the two fixturesare moved relatively toward and away from each other. Further, an inneredge of the drawing-wise contact surface projects radially inward fromthe second contact surface by not less than 10 mm so as not to contactwith the vibration-isolating base body.

It is preferable to place a pair of such vibration-isolating apparatuseson left and right portions of the interior of an engine room of anautomobile, and fix the apparatuses to rightwardly and leftwardlyinclined brackets associated with a vehicle body, by using fixing boltsprojecting downward from the lower fixtures of these apparatuses.However, vibration-isolating apparatuses may be disposed in a variousmanner other than the above.

When these apparatuses are fixed to the rightwardly and leftwardlyinclined brackets in the automobile, the fixing bolts of the upper andlower fixtures are inclined in accordance with the inclination of thebrackets in the vehicle. Therefore, even when stress should be exertedon the apparatuses in the rightward or leftward direction, the bendingstress exerted on the fixing bolts of the lower fixture also becomessmall, so that the damage to the fixing bolts and to sealing between thelower fixtures and the fixing bolts decrease.

Because the vibration-isolating apparatuses in this aspect do not have astopper mechanism for restricting a displacement in a circumferentialdirection that coincides to rightward or leftward direction of thevehicle, it is preferable to use another vibration-isolating apparatushaving a stopper mechanism for restricting a displacement in forward orbackward direction of the vehicle, on forward side or backward side ofthe engine room.

This vibration-isolating apparatus may be of various kinds as long as ithas a stopper mechanism and preferably have high vibration isolating anddamping performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cutaway front view showing an embodiment of thefirst vibration-isolating apparatus according to the present invention;

FIG. 2 is a perspective view of a metal stopper in this embodiment;

FIG. 3 is a plan view of this metal stopper;

FIG. 4 is a sectional view taken along the line D1—D1 in FIG. 3;

FIG. 5 is a sectional view taken along the line D2—D2 in FIG. 4;

FIG. 6 is a schematic view illustrating an engine support structureformed of vibration-isolating apparatuses;

FIG. 7 is a sectional view showing an embodiment of the secondvibration-isolating apparatus according to the present invention;

FIG. 8 is a perspective view of a metal stopper in this embodiment;

FIG. 9 is a plan view of this metal stopper;

FIG. 10 is a sectional view taken along the line F—F in FIG. 9; and

FIG. 11 is a side view of a metal stopper.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the vibration-isolating apparatus according tothe present invention will now be described with reference to thedrawings. The present invention is not limited to these embodiments.

FIG. 1 is a front view of a vibration-isolating apparatus showing afirst embodiment of the present invention, FIG. 2 a perspective view ofa metal stopper in this embodiment, FIG. 3 a plan view of this metalstopper, FIG. 4 a sectioned front elevation taken along the line D1—D1in FIG. 3, and FIG. 5 a sectional view taken along the line D2—D2 inFIG. 3.

As shown in the drawings, a vibration-isolating apparatus 1 in thisembodiment is for supporting an engine of an automobile in avibration-isolating manner from a vehicle body. The vibration-isolatingapparatus 1 comprises a first and upper fixture 3 secured to a bracketin an engine; a second and lower fixture 4 fixed to the vehicle body; avibration-isolating base body 5 formed of an elastic material interposedbetween the first and second fixtures 3, 4; and a stopper mechanism 6for restricting a large displacement between the fixtures 3, 4 due to anelastic deformation of the vibration-isolating base body 5. Thevibration-isolating base body 5 is bonded during its vulcanizationprocess onto each of the first and second fixtures 3, 4 so that thefirst and second fixtures are joined together. The elastic materialforming the vibration-isolating base body 5 has a rubber-like elasticityshown by rubber materials and similar materials. The term of“rubber-like elasticity” means elasticity ascribed to entropy. decreaseof increase of molecular-chain lattice structure, which elasticity ischaracterized by far smaller young modulus and. far larger elongationuntil elastic limit compared with metal or glass.

The vibration-isolating apparatus 1 of this embodiment, which is aliquid-sealed vibration-isolating apparatus, further comprises adiaphragm 7, partition 8 and an orifice 41 in an inner portion of theapparatus. The diaphragm 7 formed of a rubber film is disposed on theside of the second and lower fixture 4 so as to be opposed to thevibration base member 5. The diaphragm 7 and the vibration base member 5constitute a liquid chamber 40, into which a liquid is sealed. Thepartition 8 divides the liquid chamber 40 into two sub chambers, whichare communicated with each other through the orifice 41.

A pair of the vibration-isolating apparatuses 1 are mounted on a vehiclebody in a mutually opposed state on left and right sides of an engine,in an engine room of an automobile, to support the engine in avibration-isolating manner, as will be described later on explanation ofthe second embodiment.

In each of these vibration-isolating apparatuses 1, the first and upperfixture 3 is shaped as a flat plate, at center portion of which a fixingbolt 9 projecting upward and a positioning pin 10 for positioning ametal stopper 17 are fixedly provided. The fixing bolt 9 is screwed on abracket of the engine.

The second and lower fixture 4 has a shape of a cup or an upwardlyopened vessel. The second fixture 4 is constituted by a bottomed barrelmember 12 fixedly provided with fixing bolts 11 to be fastened to avehicle body, and a central-trunk barrel member 13 caulked as connectedto the bottomed barrel member 12. At inside of the second fixture 4, thediaphragm 7 and a partition 8 are fixed by a caulked portion 14connecting the barrel members 12, 13.

The vibration-isolating base body 5 formed of the elastic material isshaped like an umbrella and is bonded to the first fixture 3 and to thecentral-trunk barrel member 13 of the second fixture 4 at avulcanization process of the elastic material.

The stopper mechanism (stabilizer mechanism) 6 prevents an excessivedeformation of the vibration-isolating base body 5 by contacting at aportion of outer surface of the vibration-isolating base body 5, for thepurpose of size reduction in the engine room. The stopper mechanism 6 iscomprised by a stopper rubber 16 outwardly projecting from asecond-fixture-side portion of the vibration-isolating base body, and ametal stopper 17 associated with the first fixture 3.

The stopper rubber 16 is comprised by an extended flange portion 19 aextended radially outward from a portion of a flange-shaped outercircumferential edge 19 at an upper end of the central-trunk barrelmember 13; a reinforcing metal member 20 disposed obliquely on the lowerside of an outer end of the extended flange portion 19 a; and anenclosing rubber portion 21 extended from the vibration-isolating basebody 5 so as to enclose the extended flange portion 19 a and reinforcingmetal member 20.

As shown in FIG. 2, an upward-facing stopper surface 16 a of theenclosing rubber portion 21 is parallel to a plane perpendicular to thecompression and drawing directions X1, X2 (axial direction of the fixingbolt 9, i.e. axial direction of the vibration-isolating apparatus 1) ofthe vibration-isolating base body 5, or to a surface of the extendedflange portion 19 a. A downward-facing stopper surface 16 b of theenclosing rubber portion 21 is inclined at an angle range of 10°-50°(45° in a shown example of this embodiment) with respect to the surfaceof the extended flange portion 19 a that is perpendicular to thecompression and drawing directions X1, X2. The downward-facing stoppersurface 16 b is parallel to the inclined reinforcing metal member 20. Aradially-outward-facing stopper surface 16 c (facing outward in a radialdirection Y1) of the enclosing rubber portion 21, which surface isoutside of an outer edge of the extended flange portion 19 a, isparallel to the compression and drawing directions X1, X2, and isperpendicular to the surface of the extended flange portion 19 a.Circumferentially-outward-facing stopper surfaces 16 d (facing outwardin the circumferential direction Z, that is perpendicular to the papersurface of FIG. 1) of the enclosing rubber portion 21 are perpendicularto the radially-outward-facing stopper surface 16 c.

The metal stopper 17 is formed from a single piece of metal plate orsheet by bend-working such as press-working. Thickness of the metalplate or sheet is adopted to be larger than that of the extended flangeportion 19 a associated with the second fixture 4 so as to securerigidity of the metal stopper 17, or the product of the bend-working.

The metal stopper 17 is comprised by a flat base-plate portion 23; afirst and upper stopper portion 24 extending from a radially outer edgeof the flat base-plate portion so as to enclose the stopper rubber 16and restricting a displacement in the compression direction X1 of thestopper rubber 16 to a predetermined range; a second stopper portion 25formed continuously from the first stopper portion 24 and restricting adisplacement in the radial direction Y1 of the stopper rubber 16, forexample, in rightward or leftward direction of the vehicle, to apredetermined range; a third and lower stopper portion 26 formedcontinuously from the second stopper portion 25 and restricting adisplacement in the drawing direction X2 of the stopper rubber 16 to apredetermined range; and fourth stopper portions 27 formed by bendingthe metal stopper at both sides of the flat base-plate portion 23 andfirst to third stopper portions 24-26 and adapted to restrict adisplacement in the circumferential direction Z of the stopper rubber16, for example, in forward or backward direction, to a predeterminedrange.

A central part of the first stopper portion 24 bulges toward the stopperrubber 16 to form a bulge 22 that is a recess in a view from upward, sothat an downward-facing contact surface 24 a on the bulge 22 of thefirst stopper portion 24 is parallel to the upward-facing stoppersurface 16 a of the stopper rubber 16. A radially-inward-facing contactsurface 25 a of the second stopper portion 25 is parallel to theradially-outward-facing stopper surface 16 c of the stopper rubber 16,leaving a predetermined distance or clearance between the surfaces 25 aand 16 c at around 5 mm when the apparatus is mounted on the vehiclebody.

A circumferential-wise (z direction-wise) intermediate part of the thirdand lower stopper portion 26 is bent toward the stopper rubber 16 toform an inclined section 28. An upward-facing contact surface 26 a ofthe inclined section 28 inclines at an angle A (45° in a shown exampleof this embodiment) of 10°-50° with respect to a plane perpendicular tothe compression and drawing directions X1, X2 or to a surface of theextended flange portion 19 a. A radially inward edge 28 a of the contactsurface 26 a projects radially inward from the contact surface 25 a ofthe second stopper portion 25 by a distance B which is not smaller than10 mm, and which is in a range not causing contact between the radiallyinward edge 28 a and the vibration-isolating base body 5. By suchconstruction, coming-off of the metal stopper 17 from the stopper rubber16 is prevented.

Circumferentially-inward-facing contact surfaces 27 a of the fourthstopper portion 27 are in parallel to thecircumferentially-outward-facing stopper surfaces 16 d of the stopperrubber 16.

Therefore, the contact surfaces 24 a, 25 a, 26 a, 27 a disposed on theinner faces of the first to fourth stopper portions 24-27 arerespectively parallel to the stopper surfaces 16 a-16 d of the stopperrubber 16. The contact surfaces 24 a, 25 a, 26 a, 27 a are respectivelyperpendicular to the compression direction X1 in which the first andsecond fixtures 3, 4 are moved relatively toward each other; the drawingdirection X2 in which these members 3, 4 are moved relatively away fromeach other; and the radial direction Y1 perpendicular to the directionsX1, X2; and circumferential direction Z.

The flat base-plate portion 23 is adapted to make a surface-to-surfacecontact with the first and upper fixture 3. The flat base-plate portion23 has an elongated through hole 30 through which the fixing bolt 9 canbe inserted; and a positioning hole 31 through which the positioning pin10 is inserted and held, whereby the metal stopper 17 is positioned andfixed. The reason why the through hole 30 for the fixing bolt 9 iselongated in the radial direction Y is that the third stopper portion 26has to be-come to the lower side of the stopper rubber 16 by way aroundthe stopper rubber 16, when assembling of the metal stopper 17 with mainpart of the vibration-isolating apparatus 1.

Downward edges of the fourth stopper portion 27, that is, downward edgesof the contact surface extending in the circumferential direction Z, areoutwardly bent toward the Z direction at an angle C of 45°-90° (90° in ashown example of this embodiment). In this way, strength of the metalstopper is enhanced to reliably withstand a large displacement.

The liquid-sealed type vibration-isolating apparatus 1 is adapted todamp various kinds of vibrations occurring due to the operation of theengine or during the travel of the vehicle. In the vibration-isolatingapparatus 1, a vibration insulating function is based on the internalfriction occurring during the elastic deformation of thevibration-isolating base body, while a vibration damping function isbased on the effect of a liquid flow owing to the orifice 41 formed bythe partition 8 in the interior of the liquid chamber 40. Since thematter is not strictly necessary for the understanding of the presentinvention, a detailed description thereof is omitted.

The metal stopper 17 constructed as described above is assembled with amain part of the vibration-isolating apparatus 1, in a following manner.Firstly, the fixing bolt 9 for the first and upper fixture 3 is insertedthrough the through hole 30 of the metal stopper 17. At this insertedstate, the third stopper portion 26 is shifted to the lower side thestopper rubber 16 through a position on the outer side of the radiallyouter end of the stopper rubber 16 by moving around the stopper rubber16. The positioning pin 10 of the first fixture 3 is then fitted intothe positioning hole 31 of the metal stopper. The metal stopper 17 isheld firmly between the first fixture 3 and the bracket on the engine,while the second fixture 4 is fixed to the bracket on the vehicle body.

In the vibration-isolating apparatus 1 with which the metal stopper isthus combined, the contact surfaces 24 a, 25 a, 26 a, 27 a of the metalstopper 17 are parallel to the stopper surfaces 16 a-16 d of the stopperrubber 16 with keeping respective predetermined distance or clearancebetween them. For example, the clearances of around 5 mm are kept whenthe vibration-isolating apparatus is mounted on a vehicle properly. Alarge displacement exceeding a predetermined level is prevented owing tothe abutting of the stopper surfaces of the stopper rubber 16 againstcontact surfaces of the metal stopper 17.

Concretely speaking, the displacement in the compression direction X1for the vibration-isolating base body 5 is restricted by the contactsurface 24 a of the first upper stopper portion 24. The displacement inthe drawing direction X2 for the vibration-isolating base body 5 isrestricted by the contact surface 26 a of the inclined section 28 of thethird lower stopper portion 26. The displacement in the radial directionY1 of the vibration-isolating base body 5, for example, rightward orleftward direction of the vehicle is restricted by the contact surface25 a of the second stopper portion 25. The displacement in thecircumferential direction Z, for example, forward or backward directionof the vehicle is restricted by the contact surface 27 a of the fourthstopper portion 27. Since the stopper surfaces 16 a-16 d of the stopperrubber 16 and the contact surfaces 24 a, 25 a, 26 a, 27 a are keptparallel to each other, a surface pressure is low at the time ofabutting on each other. Thus, durability of the metal stopper andstopper rubber is improved.

Because the radially inward edge of the upward-facing contact surface 26a projects sufficiently toward a main part of the vibration-isolatingapparatus 1, a slip-off of the metal stopper 17 is prevented, even whena large stress is applied on the vibration-isolating base body 5momentarily in the drawing direction. Since the thickness of the metalstopper 17 is set larger than that of the flange 19, the rigidity of themetal stopper can be secured even when the metal stopper receives alarge load from the stopper rubber 16. In this way, the metal stopper 17is capable of preventing a slip-off thereof and having a highdurability.

Furthermore, the outwardly extending flanges 33 are provided on thefourth stopper portions 27 positioned on both sides of the metal stopper17, in such a manner that the flanges 33 are at substantially 90° withrespect to the fourth stopper portions 27. In this way, strength of themetal stopper 17 is further enhanced to withstand a large stress.

Since the bending angle to form the upward-facing contact surface 26 aas well as projecting distance B of the inward edge of the contactsurface 26 a are set in the above-described ranges, the slip-off of themetal stopper is prevented even when large stress is applied on thevibration-isolating base body. Thus, lasting durability and reliabilityof the vibration-isolating apparatus are secured.

FIG. 6 illustrates an engine support structure using avibration-isolating apparatuses according to the second embodiment; FIG.7 a sectional view of the vibration-isolating apparatus; FIG. 8 aperspective view of a metal stopper in the second embodiment; FIG. 9 aplan view of the same metal stopper; FIG. 10 a sectional view takenalong the line F—F in FIG. 9; and FIG. 11 a side view of the metalstopper.

As shown in the drawings, the vibration-isolating apparatus 1 in thisembodiment is of a liquid-sealed type and supports an engine E of anautomobile in a vibration-isolating manner, in the same manner as in thefirst embodiment. Also as in the first embodiment, thevibration-isolating apparatus 1 in this embodiment comprises a first andupper fixture 3 fixed to a bracket B1 of the engine; a second and lowerfixture 4 fixed to a bracket B2 of a body; a vibration-isolating basebody 5 interposed between these two fixtures and bonded to the fixturesat vulcanization process thereof; and a stopper mechanism 6 forrestricting a displacement between the fixtures 3, 4 ascribed to theelastic deformation of the vibration-isolating base body 5.

Further, as in the first embodiment, the vibration-isolating apparatus 1in this embodiment comprises a diaphragm 7, partition 8 and an orifice41 in an inner portion of the apparatus. The diaphragm 7 formed of arubber film is disposed on the side of the second and lower fixture 4 soas to be opposed to the vibration base member 5. The diaphragm 7 and thevibration base member 5 constitute a liquid chamber 40, into which aliquid is sealed. The partition 8 divides the liquid chamber 40 into twosub chambers, which are communicated with each other through the orifice41.

A pair of the vibration-isolating apparatus 1 are disposed on both theleft and right sides of the engine E in an engine room of an automobileas shown in FIG. 6, in such a manner that the vibration-isolatingapparatus 1 are opposed to each other. A fixing bolt 11 projectingdownward from the lower fixture 3 of each vibration-isolating apparatus1 is fastened to one of the left and right brackets B2, which areinclined at an angle θ, of the vehicle body. On a rear end of the engineE, another vibration-isolating apparatus 1A having a stopper mechanismrestricting displacements in forward and backward direction of thevehicle is disposed separately from the above-mentionedvibration-isolating apparatuses 1.

In each of these vibration-isolating apparatuses 1, the first and upperfixture 3, second and lower fixture 4 and vibration-isolating base body5 have the same construction as the corresponding parts of the firstembodiment mentioned above. Accordingly, the same structural parts aredesignated by the same reference numerals, and detailed descriptionsthereof are omitted.

The basic construction of a stopper rubber 16 in the stopper mechanism 6is also identical with that of the corresponding part of the firstembodiment.

The construction of an extended flange portion 19 a extended from acentral-trunk barrel member 13 into a stopper rubber 16 as well as theconstruction of a metal reinforcing member 20 and an enclosing rubberportion 21, for example, are identical with those of the correspondingparts of the first embodiment. However, acircumferential-direction-facing end surface of the stopper rubber,which faces toward a direction perpendicular to the paper surface ofFIG. 7, does not serve as a stopper surface or contact surface.

As shown in FIG. 7, an upward-facing stopper surface 16 a of theenclosing rubber portion 21 is parallel to a plane perpendicular to thecompression and drawing directions X1, X2 (axial direction of the fixingbolt 9, i.e. axial direction of the vibration-isolating apparatus 1) ofthe vibration-isolating base body 5, or to a surface of the extendedflange portion 19 a. A downward-facing stopper surface 16 b of theenclosing rubber portion 21 is inclined with respect to the surface ofthe extended flange portion 19 a that is perpendicular to thecompression and drawing directions X1, X2. The downward-facing stoppersurface 16 b is parallel to the inclined reinforcing metal member 20. Aradially-outward-facing stopper surface 16 c (facing outward in a radialdirection Y1 that coincides with rightward or leftward direction of thevehicle) of the enclosing rubber portion 21, which surface is outside ofan outer edge of the extended flange portion 19 a, is parallel to thecompression and drawing directions X1, X2, and is perpendicular to thesurface of the extended flange portion 19 a.

The metal stopper 17 in the stopper mechanism 6 is formed from a singlepiece of pressed steel plate or sheet by bend-working such aspress-working. Whereas this metal stopper 17 basically has the samestructure as that in the first embodiment, it does not have a fourthstopper portion for restricting a displacement in the circumferentialdirection, for example, forward or backward direction of the vehicle toa predetermined level.

This metal stopper 17 is formed to a thickness larger than that of theextended flange portion 19 a associated with the lower fixture 4, so asto secure rigidity of the metal stopper 17, or the product of thebend-working. The metal stopper 17 is comprised by a flat base-plateportion 23 contacting the upper fixture 3; a first and upper stopperportion 24 extending from a radially outer edge of the flat base-plateportion; a radially-inward-facing stopper portion 25, or a secondstopper portion, formed continuously from the first stopper portion 24;and a third and lower stopper portion 26 formed continuously from thesecond stopper portion 25 and restricting a displacement in the radialdirection Y1. Thus, the metal stopper 17 serves for restrictingdisplacements in upward and downward directions, and in a radialdirection.

A central part of the first stopper portion 24 bulges toward the stopperrubber 16 to form a bulge 22 that is a recess in a view from upward, sothat an downward-facing contact surface 24 a on the bulge 22 of theupper stopper portion 24 is parallel to the upward-facing stoppersurface 16 a of the stopper rubber 16. A radially-inward-facing contactsurface 25 a of the radially-inward-facing stopper portion 25 isparallel to the radially-outward-facing stopper surface 16 c of thestopper rubber 16, leaving a predetermined distance or clearance betweenthe surfaces 25 a and 16 c at around 5 mm when the apparatus is mountedon the vehicle body.

The lower stopper portion 26 inclines toward the stopper rubber 16. Anupward-facing contact surface 26 a of the lower stopper portion 26 isparallel to the downward-facing stopper surface 16 b of the stopperrubber 16.

The flat base-plate portion 23 has an elongated through hole 30 throughwhich a fixing bolt 9 can be inserted, and a positioning hole 31 throughwhich a positioning pin 10 is inserted and held. The positioning andfixing of the metal stopper 17 are done by holding the flat plateportion 23 by inserting the fixing bolt 9 and positioning pin 10therethrough. The reason why the through hole 30 for the fixing bolt 9is elongated in the radial direction Y is that the third lower stopperportion 26 has to be come to the lower side of the stopper rubber 16 byway around the stopper rubber 16, when assembling of the metal stopper17 with main part of the vibration-isolating apparatus 1.

The characteristic structure of this metal stopper 17 resides infollowings. The metal stopper 17 has downwardly oriented reinforcingflanges 32 for enhancing rigidity of the metal stopper 17 on both edgesat circumferential-wise ends of the metal stopper 17. The reinforcingflanges 32 are continuously disposed on the both edges except for aregion that is subject to interference of the stopper rubber 16 at atime of large displacement of the metal stopper 17 in a circumferentialdirection relative to the stopper rubber 16. The reinforcing flanges 32are formed by bending of the both edges of the metal stopper 17.Concretely speaking, the reinforcing flanges 32 of around 10 mm in axialdimension are formed continuously in the radial direction on the bothedges, at circumferential-wise end, of the flat plate portion 23 and anupper section of a radially-inward-facing stopper portion 25. Thesereinforcing flanges 32 are formed over substantially the whole range ofradial dimension of the metal stopper 17. In other words, thereinforcing flanges 32 extend from a radially outermost portion to aradially innermost portion (not correct in a strict sense) or an endportion associated with the positioning hole 31. No flange is formed onan edge associated with the positioning hole 31, which is an edge alongthe circumferential direction.

Further, the metal stopper 17 has a rigid reinforcing rib 34 projectingradially outward from a circumferential-direction-wise center portion ofthe metal stopper 17 except for a region having the reinforcing flange32. Concretely speaking, the reinforcing rib 34 bulges outward by adistance substantially corresponding to the thickness of the metalstopper 17 from the laterally inner stopper portion 25 to the lowerstopper portion 26. Therefore, the reinforcing flanges 32 andreinforcing rib 34 are formed to be continuous in the radial directionover whole radial dimension of the metal stopper 17 in view from thecircumferential direction.

The liquid-sealed vibration-isolating apparatus 1 is adapted to dampvarious kinds of vibrations, which occur due to the operation of theengine E or during the traveling of the vehicle, by the vibrationinsulating function based on the internal friction occurring during theelastic deformation of the vibration-isolating base body; and thevibration damping function based on the effect of a liquid flow owing tothe provision of an orifice formed in a partition in a liquid chamber.Since the structure concerning the matter is not strictly necessary forthe understanding of the present invention, a detailed descriptionthereof is omitted.

The metal stopper 17 constructed as described above is assembled with amain part of the vibration-isolating apparatus 1, in a following manner.Firstly, the fixing bolt 9 for the first and upper fixture 3 is insertedthrough the through hole 30 of the metal stopper 17. At this insertedstate, the third stopper portion 26 is shifted to the lower side thestopper rubber 16 through a position on the outer side of the radiallyouter end of the stopper rubber 16 by moving around the stopper rubber16. The positioning pin 10 of the first fixture 3 is then fitted intothe positioning hole 31 of the metal stopper. The metal stopper 17 isheld firmly between the first fixture 3 and the bracket B1 on theengine, while the second fixture 4 is fixed to the bracket B2 on thevehicle body.

By forming the reinforcing flanges 32 and reinforcing rib 34 to becontinuous with each other in the radial direction, the rigidity of themetal stopper 17 against bending is enhanced. The reinforcing flanges 32does not cause increase of a radial-direction-wise dimension of thestopper metal because the reinforcing flanges 32 are formed solely bybending the edges downwardly. Moreover, easiness or efficiency formounting the vibration-isolating apparatus is higher than that of thePrior Art 1 mentioned before. Meanwhile, the reinforcing flanges 32 andreinforcing rib 34 do not interfere with the rubber stopper 16 even whenthe metal stopper 17 is circumferentially displaced relative to therubber stopper 16 due to above-mentioned construction. Furthermore,contrary to the metal stopper of the Prior Art 2, a distance between themetal stopper 17 and stopper rubber 16 can be controlled excellentlybecause the metal stopper and elastic body are formed separately to beassembled later.

The vibration-isolating apparatuses 1 in this embodiment has no stoppermechanism for restricting a displacement in forward or backwarddirection that is a circumferential direction of the metal stopper 17 isrestricted. However, that displacement is restricted by a stoppermechanism in another vibration-isolating apparatus 1A mounted on a rearend of the engine E as shown in FIG. 6. Thus, no problems arise.

The reinforcing flanges and reinforcing rib are formed continuously overthe whole radial-direction-wise dimension of the metal stopper so thatthe metal stopper does not interfere with the stopper rubber whenrelative displacement in a circumferential direction or forward or backward direction occurs therebetween. Accordingly, the rigidity againstbending and the easiness or efficiency of fixing or mounting of themetal stopper are greatly improved.

What is claimed is:
 1. A vibration-isolating apparatus, comprising: afirst fixture including a mounting bolt; a second fixture spaced apartfrom the first fixture; a vibration-isolating base body interposedbetween and connecting together said first and second fixtures andformed of an elastic material having a rubber-like elasticity; a stopperrubber outwardly projecting from a second-fixture-side portion of thevibration-isolating base body so as to restrict a deformation of thevibration-isolating base body; a metal stopper fixed to the firstfixture so as to surround the stopper rubber; the metal stopperincluding: a base plate portion defining an elongated hole for receivingthe mounting bolt of the first fixture to fix the metal stopper to thefirst fixture, the elongated hole being elongated in a directionpermitting the metal stopper to be assembled over the stopper rubber soas to surround the stopper rubber a first contact surface extending fromthe base plate and in parallel with a compression-direction-facingsurface of the stopper rubber in which direction the first and secondfixtures are moved relatively toward each other; a second contactsurface in parallel with a radial-direction-facing surface of thestopper rubber which radial direction is perpendicular to thecompression direction; a third contact surface in parallel with adrawing-direction-facing surface of the stopper rubber in whichdirection the first and second fixtures are moved away from each other;and a fourth contact surface in parallel with acircumferential-direction-facing surface of the stopper rubber; thestopper rubber including a portion of a circumferential edge of thefirst fixture extended radially outward to form an extended fixtureportion that is enclosed by the stopper rubber having a thicknessgreater than that of the extended fixture portion; the fourth contactsurface of the metal stopper having an edge bent outwardly at an anglerange of 45°-90° with respect to the fourth contact surface to form acircumferential-direction-wise outward flange; and the third contactsurface being inclined at an angle in a range of 10°-50° with respect toa plane perpendicular to the compression and drawing directions, while aradially inner edge of the third contact surface projects radiallyinward from the second contact surface by not less than 10 mm and so asnot to contact with the vibration-isolating base body.
 2. Avibration-isolating apparatus, comprising: a first fixture including amounting bolt; a second fixture spaced apart from the first fixture; avibration-isolating base body interposed between and connecting togethersaid first and second fixtures and formed of an elastic material havinga rubber-like elasticity; a stopper rubber outwardly projecting from asecond-fixture-side portion of the vibration-isolating base body so asto restrict a deformation of the vibration-isolating base body; a metalstopper fixed to the first fixture so as to surround the stopper rubber;the metal stopper including: a base plate portion defining an elongatedhole for receiving the mounting bolt of the first fixture to fix themetal stopper to the first fixture, the elongated hole being elongatedin a direction permitting the metal stopper to be assembled over thestopper rubber so as to surround the stopper rubber a first contactsurface extending from the base plate and in parallel with acompression-direction-facing surface of the stopper rubber in whichdirection the first and second fixtures are moved relatively toward eachother; a second contact surface in parallel with aradial-direction-facing surface of the stopper rubber which radialdirection is perpendicular to the compression direction; a third contactsurface in parallel with a drawing-direction-facing surface of thestopper rubber in which direction the first and second fixtures aremoved away from each other; and a fourth contact surface in parallelwith a circumferential -direction-facing surface of the stopper rubber;the fourth contact surface of the metal stopper having an edge bentoutwardly at an angle range of 45°-90° with respect to the fourthcontact surface to form a circumferential-direction-wise outward flange;and the third contact surface being inclined at an angle in a range of10°-50° with respect to a plane perpendicular to the compression anddrawing directions, while a radially inner edge of the third contactsurface projects radially inward from the second contact surface by notless than 10 mm and so as not to contact with the vibration-isolatingbase body.
 3. A vibration-isolating apparatus, comprising: a firstfixture including a mounting bolt; a second fixture spaced apart fromthe first fixture; a vibration-isolating base body interposed betweenand connecting together said first and second fixtures and formed of anelastic material hazing a rubber-like elasticity; a stopper rubberoutwardly projecting from a second-fixture-side portion of thevibration-isolating base body so as to restrict a deformation of thevibration-isolating base body; a metal stopper fixed to the firstfixture so as to surround the stopper rubber; the metal stopperincluding: a base plate portion defining an elongated hole for receivingthe mounting bolt of the first fixture to fix the metal stopper to thefirst fixture, the elongated hole being elongated in a directionpermitting the metal stopper to be assembled over the stopper rubber soas to surround the stopper rubber a first contact surface extending fromthe base plate and in parallel with a compression-direction-facingsurface of the stopper rubber in which direction the first and secondfixtures are moved relatively toward each other; a second contactsurface in parallel with a radial-direction-facing surface of thestopper rubber which radial direction is perpendicular to thecompression direction; a third contact surface in parallel with adrawing-direction-facing surface of the stopper rubber in whichdirection the first and second fixtures are moved away from each other;and a fourth surface in parallel with a circumferential-direction-facingsurface of the stopper rubber; and the third contact surface beinginclined at an angle in a range of 10°-50° with respect to a planeperpendicular to the compression and drawing directions, while aradially inner edge of the third contact surface projects radiallyinward from the second contact surface by not less than 10 mm and so asnot to contact with the vibrating-isolating base body.
 4. Avibration-isolating apparatus comprising: a first fixture; a secondfixture spaced apart from the first fixture; a vibration-isolating basebody interposed between and connecting together said first and secondfixtures and formed of an elastic material having a rubber-likeelasticity; a stopper rubber outwardly projecting from asecond-fixture-side portion of the vibration-isolating base body so asto restrict a deformation of the vibration-isolating base body; a metalstopper fixed to the first fixture so as to surround the stopper rubber;the metal stopper including: a first contact surface in parallel with acompression-direction-facing surface of the stopper rubber in whichdirection the first and second fixtures are moved relatively toward eachother; a second contact surface in parallel with aradial-direction-facing surface of the stopper rubber which radialdirection is perpendicular to the compression direction; a third contactsurface in parallel with a drawing-direction-facing surface of thestopper rubber in which direction the first and second fixtures aremoved away from each other; a fourth contact surface in parallel with acircumferential-direction-facing surface of the stopper rubber; and thethird contact surface being inclined at an angle in a range of 10°-50°with respect to a plane perpendicular to the compression and drawingdirections, while a radially inner edge of the third contact surfaceprojects radially inward from the second contact surface by not lessthan 10 mm and so as not to contact with the vibration-isolating basebody.